Trump is/was wildly unpopular among the majority of industrialised nations, AFAIK.
As for the reasons why - he is obviously not a clever man who has absolutely no business being near any position of power, who now has a cult like following among others who are even dumber than he (some of whom are in this thread)
Non Americans who support Trump tend to be reactionary folks with little interest in policy or history, but prefer to communicate their political preferences in memes. At least from my experience.